Arithmetical properties of Multiple Ramanujan sums

In the present paper, we introduce a multiple Ramanujan sum for arithmetic functions, which gives a multivariable extension of the generalized Ramanujan sum studied by D. R. Anderson and T. M. Apostol. We then find fundamental arithmetic properties of the multiple Ramanujan sum and study several types of Dirichlet series involving the multiple Ramanujan sum. As an application, we evaluate higher-dimensional determinants of higher-dimensional matrices, the entries of which are given by values of the multiple Ramanujan sum.Comment: 19 page

Species-specific, pan-European diameter increment models based on data of 2.3 million trees

ResearchBackground: Over the last decades, many forest simulators have been developed for the forests of individual European countries. The underlying growth models are usually based on national datasets of varying size, obtained from National Forest Inventories or from long-term research plots. Many of these models include country- and location-specific predictors, such as site quality indices that may aggregate climate, soil properties and topography effects. Consequently, it is not sensible to compare such models among countries, and it is often impossible to apply models outside the region or country they were developed for. However, there is a clear need for more generically applicable but still locally accurate and climate sensitive simulators at the European scale, which requires the development of models that are applicable across the European continent. The purpose of this study is to develop tree diameter increment models that are applicable at the European scale, but still locally accurate. We compiled and used a dataset of diameter increment observations of over 2.3 million trees from 10 National Forest Inventories in Europe and a set of 99 potential explanatory variables covering forest structure, weather, climate, soil and nutrient deposition. Results: Diameter increment models are presented for 20 species/species groups. Selection of explanatory variables was done using a combination of forward and backward selection methods. The explained variance ranged from 10% to 53% depending on the species. Variables related to forest structure (basal area of the stand and relative size of the tree) contributed most to the explained variance, but environmental variables were important to account for spatial patterns. The type of environmental variables included differed greatly among species. Conclusions: The presented diameter increment models are the first of their kind that are applicable at the European scale. This is an important step towards the development of a new generation of forest development simulators that can be applied at the European scale, but that are sensitive to variations in growing conditions and applicable to a wider range of management systems than before. This allows European scale but detailed analyses concerning topics like CO2 sequestration, wood mobilisation, long term impact of management, etcinfo:eu-repo/semantics/publishedVersio

Anti-Inflammatory Role of the cAMP Effectors Epac and PKA: Implications in Chronic Obstructive Pulmonary Disease

Cigarette smoke-induced release of pro-inflammatory cytokines including interleukin-8 (IL-8) from inflammatory as well as structural cells in the airways, including airway smooth muscle (ASM) cells, may contribute to the development of chronic obstructive pulmonary disease (COPD). Despite the wide use of pharmacological treatment aimed at increasing intracellular levels of the endogenous suppressor cyclic AMP (cAMP), little is known about its exact mechanism of action. We report here that next to the β2-agonist fenoterol, direct and specific activation of either exchange protein directly activated by cAMP (Epac) or protein kinase A (PKA) reduced cigarette smoke extract (CSE)-induced IL-8 mRNA expression and protein release by human ASM cells. CSE-induced IκBα-degradation and p65 nuclear translocation, processes that were primarily reversed by Epac activation. Further, CSE increased extracellular signal-regulated kinase (ERK) phosphorylation, which was selectively reduced by PKA activation. CSE decreased Epac1 expression, but did not affect Epac2 and PKA expression. Importantly, Epac1 expression was also reduced in lung tissue from COPD patients. In conclusion, Epac and PKA decrease CSE-induced IL-8 release by human ASM cells via inhibition of NF-κB and ERK, respectively, pointing at these cAMP effectors as potential targets for anti-inflammatory therapy in COPD. However, cigarette smoke exposure may reduce anti-inflammatory effects of cAMP elevating agents via down-regulation of Epac1

Imaging findings in noncraniofacial childhood rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood. This paper is focuses on imaging for diagnosis, staging, and follow-up of noncraniofacial RMS

Spatial theory and human behavior

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45971/1/10110_2005_Article_BF01952731.pd

Performance of non-invasive tests and histology for the prediction of clinical outcomes in patients with non-alcoholic fatty liver disease: an individual participant data meta-analysis

BackgroundHistologically assessed liver fibrosis stage has prognostic significance in patients with non-alcoholic fatty liver disease (NAFLD) and is accepted as a surrogate endpoint in clinical trials for non-cirrhotic NAFLD. Our aim was to compare the prognostic performance of non-invasive tests with liver histology in patients with NAFLD.MethodsThis was an individual participant data meta-analysis of the prognostic performance of histologically assessed fibrosis stage (F0–4), liver stiffness measured by vibration-controlled transient elastography (LSM-VCTE), fibrosis-4 index (FIB-4), and NAFLD fibrosis score (NFS) in patients with NAFLD. The literature was searched for a previously published systematic review on the diagnostic accuracy of imaging and simple non-invasive tests and updated to Jan 12, 2022 for this study. Studies were identified through PubMed/MEDLINE, EMBASE, and CENTRAL, and authors were contacted for individual participant data, including outcome data, with a minimum of 12 months of follow-up. The primary outcome was a composite endpoint of all-cause mortality, hepatocellular carcinoma, liver transplantation, or cirrhosis complications (ie, ascites, variceal bleeding, hepatic encephalopathy, or progression to a MELD score ≥15). We calculated aggregated survival curves for trichotomised groups and compared them using stratified log-rank tests (histology: F0–2 vs F3 vs F4; LSM: 2·67; NFS: 0·676), calculated areas under the time-dependent receiver operating characteristic curves (tAUC), and performed Cox proportional-hazards regression to adjust for confounding. This study was registered with PROSPERO, CRD42022312226.FindingsOf 65 eligible studies, we included data on 2518 patients with biopsy-proven NAFLD from 25 studies (1126 [44·7%] were female, median age was 54 years [IQR 44–63), and 1161 [46·1%] had type 2 diabetes). After a median follow-up of 57 months [IQR 33–91], the composite endpoint was observed in 145 (5·8%) patients. Stratified log-rank tests showed significant differences between the trichotomised patient groups (p<0·0001 for all comparisons). The tAUC at 5 years were 0·72 (95% CI 0·62–0·81) for histology, 0·76 (0·70–0·83) for LSM-VCTE, 0·74 (0·64–0·82) for FIB-4, and 0·70 (0·63–0·80) for NFS. All index tests were significant predictors of the primary outcome after adjustment for confounders in the Cox regression.InterpretationSimple non-invasive tests performed as well as histologically assessed fibrosis in predicting clinical outcomes in patients with NAFLD and could be considered as alternatives to liver biopsy in some cases

Recurring Intracranial Malignant Peripheral Nerve Sheath Tumor: Case Report and Systematic Review of the Literature

To report the clinical presentation and management of an intracranial frontoparietal malignant peripheral nerve sheath tumor (MPNST) and its recurrence in a 6-year-old girl, along with a systematic review of the literature. A previously healthy 6-year-old girl presented with severe signs of increased intracranial pressure. Magnetic resonance imaging (MRI) revealed a large heterogeneously enhancing mass at the right frontoparietal convexity. The tumor was completely removed, the histological diagnosis was MPNST, and the patient underwent adjuvant radio- and chemotherapy. Fifteen months later, MRI revealed a small local recurrence. After upfront chemotherapy, the recurrence was removed in a radical, ie, true oncological, neuronavigationally guided, en bloc resection, including approximately 1 cm surrounding gray and white matter and overlying dura mater. Neuropathological examination revealed tumor-free margins. The patient again received adjuvant chemotherapy. Four years after diagnosis and 20 months after cessation of adjuvant therapy, there are no signs of tumor recurrence. The literature search resulted in 17 cases of intracranial MPNSTs not associated with cranial nerves. Despite macroscopically complete resection in many cases and adjuvant radio- and chemotherapy, overall survival was poor, with only 5 patients still alive upon publication (including the current patient). Intracranial MPNSTs not associated with cranial nerves are extremely rare and highly malignant tumors with poor overall survival, probably because of infiltrating growth into surrounding brain tissue. We therefore advocate consideration of nonconventional true oncological en bloc resection when approaching this rare tumor or its recurrenc

The ROCOCO performance scoring system translates dosimetric differences into clinically relevant endpoints: Comparing IMPT to VMAT in an example pilocytic astrocytoma dataset

Contains fulltext : 232798.pdf (Publisher’s version ) (Open Access)BACKGROUND AND PURPOSE: Proton therapy is expected to outperform photon-based treatment regarding organs at risk (OAR) sparing but to date there is no method to practically measure clinical benefit. Here, we introduce the novel ROCOCO Performance Scoring System (RPSS) translating dose differences into clinically relevant endpoints and apply this to a treatment plan comparison of volumetric modulated arc therapy (VMAT) and intensity modulated proton therapy (IMPT) in 20 pilocytic astrocytoma patients. MATERIAL AND METHODS: The RPSS was developed on the basis of expert-based weighting factors and toxicity scores per OAR. The imaging datasets of 20 pilocytic astrocytoma patients having undergone radiotherapy were included in this in silico dosimetric comparison trial as proof of principle. For each of these patients, treatment plans to a total dose of 54 Gy (RBE) were generated for VMAT and IMPT and these were compared regarding radiation dose to the clinical target volume (CTV) and OARs. The RPSS was calculated for each treatment plan comparing VMAT and IMPT. RESULTS: In 40 analysed treatment plans, the average and low dose volumes to various OARs were significantly reduced when using IMPT compared to VMAT (p < 0.05). Using the RPSS, a significant difference between both treatment modalities was found, with 85% of the patients having a lower RPSS in favour of the IMPT plan. CONCLUSION: There are dosimetric differences between IMPT and VMAT in pilocytic astrocytoma patients. In absence of clinically validated NTCP models we introduce the RPSS model in order to objectively compare treatment modalities by translating dosimetric differences in potential clinical differences

Palliative radiation therapy for AIDS-associated Kaposi's sarcoma by using a single fraction of 800 cGy

A single radiation fraction of 800 cGy was used in the treatment of acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma (KS). A total of 74 radiation treatments was given to a total of 31 patients. Of all 74 evaluable treatments, there were 25 objective major responses (6 complete, 19 partial) according to the WHO criteria, while 67 treatments resulted in subjective palliation of the main reason to treat (cosmetic discomfort, pain, or oedema). However, it appeared that the duration of these responses was rather short; in 23 of 36 radiation treatments with a follow-up of more than 4 months, progression of the tumour was seen within that time, while the palliative effect outlasted the survival of the patients in only four cases. It is concluded that a single dose of 800 cGy is an effective treatment for patients with a predicted survival of only a few months, and it should be determined whether a higher fractionated dose improves duration of responses, especially for patients with a good performanc